scholarly journals Silver(I) complexes of imidazolidine-2-thione and triphenylphosphines: Solid-state, solution NMR and antimicrobial activity studies

2007 ◽  
Vol 21 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Norah O. Al-Zamil ◽  
Khulood A. Al-Sadhan ◽  
Anvarhusein A. Isab ◽  
Mohamed I.M. Wazeer ◽  
Abdul Rehman A. Al-Arfaj
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Solid State ◽  
Solid State Nmr ◽  
Mixed Ligand ◽  
The Other ◽  
Solution Nmr ◽  
Nmr Studies ◽  
Gram Negative ◽  
E Coli

Mixed ligand complexes of Ag(I) with triphenylphosphine (PPh3), triphenylphosphine sulfide (SPPh3), triphenylphosphine selenide (SePPh3) and Imidazolidine-2-thione (Imt) have been prepared. The solution as well as solid state NMR studies have been carried out to characterize these complexes. Both solid and solution NMR show the coordination via thione group on one side and (S/Se) or PPh3on the other side. A higher antimicrobial activity is shown by [ImtAgPPh3]Cl complex against gram negativePseudomonas aeruginosa(P. aeruginosa) andEscherichia coli(E. coli) compared to the other two complexes i.e. [ImtAgSPPh3]Cl and [ImtAgSePPh3]Cl.

Disinfection of Fruits with Activated Water

2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova
Keyword(s):  
Antimicrobial Activity ◽  
Aqueous Solutions ◽  
Antimicrobial Properties ◽  
The Other ◽  
Gram Negative Bacteria ◽  
High Antimicrobial Activity ◽  
Gram Negative ◽  
E Coli ◽  
Number Of Microorganisms ◽  
Lower Effect

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.

scholarly journals In Vitro Activity of Newer and Conventional Antimicrobial Agents, Including Fosfomycin and Colistin, against Selected Gram-Negative Bacilli in Kuwait

Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 75 ◽  
Author(s):  
Wadha Alfouzan ◽  
Rita Dhar ◽  
David Nicolau
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
The Other ◽  
In Vitro Activity ◽  
Limited Data ◽  
Gram Negative ◽  
E Coli ◽  
Microbroth Dilution

Limited data are available on susceptibilities of these organisms to some of the recently made accessible antimicrobial agents. The in vitro activities of newer antibiotics, such as, ceftolozane/tazobactam (C/T) and ceftazidime/avibactam (CZA) along with some “older” antibiotics, for example fosfomycin (FOS) and colistin (CL) were determined against selected strains (resistant to ≥ 3 antimicrobial agents) of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Minimum inhibitory concentrations (MIC) were determined by Clinical and Laboratory Standards Institute microbroth dilution. 133 isolates: 46 E. coli, 39 K. pneumoniae, and 48 P. aeruginosa were tested. Results showed that E. coli isolates with MIC50/90, 0.5/1 μ g / mL for CL; 4/32 μ g / mL for FOS; 0.25/32 μ g / mL for C/T; 0.25/8 μ g / mL for CZA, exhibited susceptibility rates of 95.7%, 97.8%, 76.1%, and 89.1%, respectively. On the other hand, K. pneumoniae strains with MIC50/90, 0.5/1 μ g / mL for CL; 256/512 μ g / mL for FOS; 2/128 μ g / mL for C/T; 0.5/128 μ g / mL for CZA showed susceptibility rates of 92.3%, 7.7%, 51.3%, and 64.1%, respectively. P. aeruginosa isolates with MIC50/90, 1/1 μ g / mL for CL; 128/128 μ g / mL for C/T; 32/64 μ g / mL for CZA presented susceptibility rates of 97.9%, 33.3%, and 39.6%, respectively. Higher MICs were demonstrated against most of the antibiotics. However, CL retained efficacy at low MICs against most of the isolates tested.

scholarly journals Phospholipid distribution in the cytoplasmic membrane of Gram-negative bacteria is highly asymmetric, dynamic, and cell shape-dependent

2020 ◽  
Vol 6 (23) ◽  
pp. eaaz6333 ◽  
Author(s):  
Mikhail Bogdanov ◽  
Kyrylo Pyrshev ◽  
Semen Yesylevskyy ◽  
Sergey Ryabichko ◽  
Vitalii Boiko ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Physical Properties ◽  
Cell Shape ◽  
Yersinia Pseudotuberculosis ◽  
Cytoplasmic Membrane ◽  
The Other ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Phospholipid Distribution

The distribution of phospholipids across the inner membrane (IM) of Gram-negative bacteria is unknown. We demonstrate that the IMs of Escherichia coli and Yersinia pseudotuberculosis are asymmetric, with a 75%/25% (cytoplasmic/periplasmic leaflet) distribution of phosphatidylethanolamine (PE) in rod-shaped cells and an opposite distribution in E. coli filamentous cells. In initially filamentous PE-lacking E. coli cells, nascent PE appears first in the periplasmic leaflet. As the total PE content increases from nearly zero to 75%, cells progressively adopt a rod shape and PE appears in the cytoplasmic leaflet of the IM. The redistribution of PE influences the distribution of the other lipids between the leaflets. This correlates with the tendency of PE and cardiolipin to regulate antagonistically lipid order of the bilayer. The results suggest that PE asymmetry is metabolically controlled to balance temporally the net rates of synthesis and translocation, satisfy envelope growth capacity, and adjust bilayer chemical and physical properties.

scholarly journals Antimicrobial Activity of Prulifloxacin Tested against a Worldwide Collection of Gastroenteritis-Producing Pathogens, Including Those Causing Traveler's Diarrhea

2008 ◽  
Vol 53 (3) ◽  
pp. 1221-1224 ◽  
Author(s):  
Thomas R. Fritsche ◽  
Douglas J. Biedenbach ◽  
Ronald N. Jones
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Active Component ◽  
Antimicrobial Agents ◽  
Clinical Use ◽  
Gram Negative ◽  
Similar Activity ◽  
Surveillance Studies ◽  
E Coli ◽  
Highly Active

ABSTRACT Prulifloxacin, the prodrug of ulifloxacin (active component), is a newer fluoroquinolone with broad activity against enteric and nonenteric gram-negative bacilli. Ulifloxacin and other oral comparator agents were tested for activity against 582 gastroenteritis strains from global surveillance studies. Ulifloxacin was highly active against Escherichia coli, Salmonella spp., Shigella spp., Yersinia spp., Vibrio spp., Aeromonas spp., and Plesiomonas spp. (MIC50s and MIC90s, ≤0.03 μg/ml and ≤0.06 μg/ml, respectively). Only rare Aeromonas spp., Campylobacter spp., and E. coli displayed elevated MIC results (≥4 μg/ml). Ciprofloxacin exhibited similar activity but was two- to fourfold less potent. Presently approved for clinical use in certain European countries and Japan, ulifloxacin was the most active of the antimicrobial agents tested against these gastroenteritis-causing pathogens.

scholarly journals Oxidative Stress and Antimicrobial Activity of Chromium(III) and Ruthenium(II) Complexes onStaphylococcus aureusandEscherichia coli

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Paulina L. Páez ◽  
Claudia M. Bazán ◽  
María E. Bongiovanni ◽  
Judith Toneatto ◽  
Inés Albesa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Agents ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Diimine Ligands

The prevalence of antibiotic resistance has resulted in the need for new approaches to be developed to combat previously easily treatable infections. The main aim of this work was to establish the potential of the syntheticα-diimine chromium(III) and ruthenium(II) complexes (where theα-diimine ligands are bpy = 2,2-bipyridine, phen = 1,10-phenanthroline, and dppz = dipyrido[3,2-a:2′,3′-c]-phenazine) like [Cr(phen)3]3+, [Cr(phen)2(dppz)]3+, [Ru(phen)3]2+, and [Ru(bpy)3]2+as antibacterial agents by generating oxidative stress. The [Cr(phen)3]3+and [Cr(phen)2(dppz)]3+complexes showed activity against Gram positive and Gram negative bacteria with minimum inhibitory concentrations (MICs) ranging from 0.125 μg/mL to 1 μg/mL, while [Ru(phen)3]2+and [Ru(bpy)3]2+do not exhibit antimicrobial activity against the two bacterial genera studied at the concentration range used. When ciprofloxacin was combined with [Cr(phen)3]3+for the inhibition ofStaphylococcus aureusandEscherichia coli, an important synergistic effect was observed, FIC 0.066 forS. aureusand FIC 0.064 forE. coli. The work described here shows that chromium(III) complexes are bactericidal forS. aureusandE. coli. Our results indicate thatα-diimine chromium(III) complexes may be interesting to open new paths for metallodrug chemotherapy against different bacterial genera since some of these complexes have been found to exhibit remarkable antibacterial activities.

scholarly journals Structure and Orientation of Pardaxin Determined by NMR Experiments in Model Membranes

2004 ◽  
Vol 279 (44) ◽  
pp. 45815-45823 ◽  
Author(s):  
Fernando Porcelli ◽  
Bethany Buck ◽  
Dong-Kuk Lee ◽  
Kevin J. Hallock ◽  
Ayyalusamy Ramamoorthy ◽  
...  
Keyword(s):  
Solid State ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Solid State Nmr ◽  
Double Resonance ◽  
Slow Motion ◽  
Solution Nmr ◽  
Helical Conformation ◽  
Hydrophobic Core ◽  
Nmr Studies

Pardaxins are a class of ichthyotoxic peptides isolated from fish mucous glands. Pardaxins physically interact with cell membranes by forming pores or voltage-gated ion channels that disrupt cellular functions. Here we report the high-resolution structure of synthetic pardaxin Pa4 in sodium dodecylphosphocholine micelles, as determined by1H solution NMR spectroscopy. The peptide adopts a bend-helix-bend-helix motif with an angle between the two structure helices of 122 ± 9°, making this structure substantially different from the one previously determined in organic solvents. In addition, paramagnetic solution NMR experiments on Pa4 in micelles reveal that except for the C terminus, the peptide is not solvent-exposed. These results are complemented by solid-state NMR experiments on Pa4 in lipid bilayers. In particular,13C-15N rotational echo double-resonance experiments in multilamellar vesicles support the helical conformation of the C-terminal segment, whereas2H NMR experiments show that the peptide induces considerable disorder in both the head-groups and the hydrophobic core of the bilayers. These solid-state NMR studies indicate that the C-terminal helix has a transmembrane orientation in DMPC bilayers, whereas in POPC bilayers, this domain is heterogeneously oriented on the lipid surface and undergoes slow motion on the NMR time scale. These new data help explain how the non-covalent interactions of Pa4 with lipid membranes induce a stable secondary structure and provide an atomic view of the membrane insertion process of Pa4.

scholarly journals COMPARISON OF ANTIBACTERIAL ACTIVITY OF HONEY AGAINST AEROBIC AND ANAEROBIC BACTERIA

2021 ◽  
pp. 41-43
Author(s):  
S. DHANARAJ ◽  
S. S. M. UMAMAGESWARI ◽  
M. MALAVIKA ◽  
G. BHUVANESHWARI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Clostridium Perfringens ◽  
Anaerobic Bacteria ◽  
The Other ◽  
E Coli ◽  
Diffusion Technique ◽  
Aerobic And Anaerobic

Objective: To compare the antibacterial activity of honey against aerobic and anaerobic bacteria. Methods: Honey is extracted from the honey comb by trained persons. Antimicrobial activity of honey is performed by Agar Cup Diffusion technique for 3 bacteria Staphylococcus aureus, E. coli and Clostridium perfringens. Results: By performing the technique with proper guidance, it is observed that the Staphylococcus aureus specimen shows sensitivity to honey whereas the other two specimens Escherichia coli and clostridium perfringens doesn’t show any sensitivity to honey. Conclusion: Due to its vast antibacterial activity of honey, it can be used along with other antibiotics to increase its efficiency.

scholarly journals COMPARISON OF ANTIBACTERIAL ACTIVITY OF GARLIC AGAINST AEROBIC AND ANAEROBIC BACTERIA

2021 ◽  
pp. 44-46
Author(s):  
K. G. DHANUSH ◽  
S. S. M. UMAMAGESWARI ◽  
M. MALAVIKA ◽  
G. BHUVANESHWARI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Clostridium Perfringens ◽  
Anaerobic Bacteria ◽  
The Other ◽  
E Coli ◽  
Diffusion Technique ◽  
Aerobic And Anaerobic

Objective: To compare the antibacterial activity of garlic against aerobic and anaerobic bacteria. Methods: Antimicrobial activity of garlic is performed by Agar cup diffusion technique for 3 bacteria Staphylococcus aureus, E. coli and clostridium perfringens. Results: By performing the technique with proper guidance, it is observed that the Staphylococcus aureus specimen shows sensitivity to garlic whereas the other two specimens Escherichia coli and clostridium perfringens doesn’t show any sensitivity to garlic. Conclusion: Due to its vast antibacterial activity of garlic, it can be used along with other antibiotics to increase its efficiency.

scholarly journals Synergistic Interactions of Vancomycin with Different Antibiotics against Escherichia coli: Trimethoprim and Nitrofurantoin Display Strong Synergies with Vancomycin against Wild-Type E. coli

2014 ◽  
Vol 59 (1) ◽  
pp. 276-281 ◽  
Author(s):  
Alice Zhou ◽  
Tina Manzhu Kang ◽  
Jessica Yuan ◽  
Casey Beppler ◽  
Caroline Nguyen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
The Other ◽  
Gram Negative Bacteria ◽  
Functional Categories ◽  
Wild Type ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Synergistic Interactions ◽  
Pairwise Interactions

ABSTRACTGram-negative bacteria are normally resistant to the antibiotic vancomycin (VAN), which cannot significantly penetrate the outer membrane. We usedEscherichia colimutants that are partially sensitive to VAN to study synergies between VAN and 10 other antibiotics representing six different functional categories. We detected strong synergies with VAN and nitrofurantoin (NTR) and with VAN and trimethoprim (TMP) and moderate synergies with other drugs, such as aminoglycosides. These synergies are powerful enough to show the activity of VAN against wild-typeE. coliat concentrations of VAN as low as 6.25 μg/ml. This suggests that a very small percentage of exogenous VAN does enterE. colibut normally has insignificant effects on growth inhibition or cell killing. We used the results of pairwise interactions with VAN and the other 10 antibiotics tested to place VAN into a functional category of its own, as previously defined by Yeh et al. (P. Yeh, A. I. Tschumi, and R. Kishony, Nat Genet 28:489–494, 2006,http://dx.doi.org/10.1038/ng1755).

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